Pontoon assembly and method of using the same



Dec. 18,1945. I w. w. MACFARREN ,3

PONTOON ASSEMBLY AND METHOD OF USING THE SAME Filed Nov. 20, 1940 2 Sheets-Sheet 1 INVENTOR.

Dec. 18, 1945. w. w. MACFARREN 1 2,391,059

PONTOON ASSEMBLY AND METHOD OF USINGTHE SAME Filed Nov. 20, 1940 2 Sheets-Sheet 2 ININILNI 7 7 mama. 1 F16 /1 Patented Dec. 18, 1945' UNITED PONTOON ASSEIWBLY AND METHOD OF USING THE SAME Walter W. Macfarren, Los :Angeles, Calif.

Application November 20, 1940, Serial No. 366,507

20 Claims. 114-05) My invention comprises a plurality of pontoons arranged in a connected line or group for simultaneous operation, and usually set across a water way or ship channel, for the purpose of acting as a gate to prevent, or permit, movement of water borne material or objects, either above or below the surface of the water, along said water way. 1

The present application consists in part of material divided out of my application Serial No. 198,093,,now Patent No. 2,224,844, for Protective devices for pipe lines, and in part of new material herein disclosed The objects of my invention are:

1. To provide a line of pontoons which may be permanently stretched across a channel or water way with its ends appropriately anchored, and made to rise or fall by expulsion of water from, or admission of water to, all the pontoons at the same time.

2. To provide an individual reservoir of compressed air for each pontoon, in combination with means for charging and discharging all of said reservoirs at the same time.

3. To provide manually operated controls for causing the pontoon assembly to rise or fall, operatable from either an adjacent or a distant point, and to provide automatic means for causing the pontoons to either rise or fall, as desired, upon the occurrence of a substantial seismic shock.

4. To provide a method of gradually charging the pontoon reservoirs by an air line from the shore.

5. To provide a method of quickly discharging the water from the pontoons to raise them, by the use of the stored air in the pontoon reservoirs.

6. To provide a method of quickly admitting Water to all the pontoons, to sink them.

7. To provide pressure operated controls for operating the pontoons from the shore, according to one or more of the above methods.

8. To provide means whereby the rise and fall of the pontoons may be entirely under water, so that the pontoons are at all times concealed.

9. To provide various attachments for the pontoons to serve a variety of useful purposes.

10. And in general to provide a rugged, practical, and useful assembly of flexibly connected pontoons for such uses as may be found for them.

As one suggested use, such a line of pontoons may be employed to support a skimming dam to extend above the surface of the water, and to prevent the passage of floating oil, floating timber or cargo of .any kind, or floating debris. As another use, such a line of pontoons may be employed to support a chain or cables to close a river or harbor entrance against movement of surface shipping. A third use might be to support a fish net across a fish run, the lower edge of the net being weighted to anchor it to the bottom.

A similar use would be to close a river or harbor entrance by cables or chains suspended from the pontoons in the form of a net, to prevent the entrance or egress of submarine boats. In this case the pontoons should preferably be kept continuously under water by limiting their rise from a position at or near the bottom, to a level a few feet below the surface.

This may be done either by attaching anchors to the submarine net so as to prevent the rise of the pontoonsabove a predetermined level, or by limiting the volume of the displacement air supplied to the pontoons to just enough to float them to said level with a certain weight of net attached. This may be easily done by limiting the air pressure.

By day the pontoon assembly and the attached net could lie on thebottom, and at night the pontoons could rise to the level chosen, say just below the draft of small boats, and both day and night the pontoons would be invisible, except possibly from the air,

As an auxiliary device to be used in connection with a submarine net, I show apparatus in Fig. 4 which may indicate the presence of a submarine boat in contact with the net.

Since the use of skimming dams and the use of submarine nets are both broadly old, the present application is confined to the use of a flexible pontoon assembly, the construction of the same, and the method or methods of operating the same. a

In the drawings,

Fig. 1 is an elevation of a pontoon assembly according to my invention, moored to the banks of a waterway by cables, and supporting a submarine net having its lower edge positioned by anchors resting on the bottom.

Fig. 2 is an elevation of a pontoon assembly according to my invention, slidably attached to vertical posts, and provided with an attached skimming dam.

Fig. 3 is an enlarged elevation of one form of a submarine net, showing the method of attaching it to the pontoons, etc.

Fig. 4c is a part of a diagram of apparatus for Fig. 7 is a sectional elevation of a blow out.

valve.

Fig. valve.

Fig. 9 is a vertical longitudinalpontoon sec-,

tion.

Fig. 10 is an end elevation of the same.

Fig. 11 is a vertical section of a flexible connector between two adjacent pontoons.

Fig. 12 is a cross section of the same taken on the line |2--|2 of Fig. 11.

Fig. 13 is an elevation of one of the end pontoons, and one of the vertical anchor posts therefor.

Fig. 14 is an elevation of a second type of seismic control device.

Referring to Figs. 1 and 3, a ship channel I may be provided with a pair of masonry anchorages or piers 2 and 3, and a line or connected pontoons 4, having flexible connectors 5, may be anchored to piers 2 and 3 by chains or cables 6 and I. The detailed construction of the pontoons, and their connections will be described later.

To this line of pontoons there may be attached a steel submarine net, one form of which may be constructed as shown in Fig. 3, in which pairs of angles 8 may be fastened to the shell of each pontoon 4, and chains ||l may be connected to the angles 8, by pins 9. r

At the lower end of each chain In, there may be attached an anchor H, in the form of a ball, or of any other suitable form, and the lengths of the chains ||l may be so chosen that Where the bottom- I2 is uneven, as shown in Fig. 1, the pontoons when intheir upper position as shown, may

8 is a similar view of a pontoon vent form a level assembly at such a distance below the water line l3, as to permit the passage. of small boats M.

Horizontal chains l6 and I1 may be connected to the vertical chains l0, thus forming a net with rectangular or square meshes. Assuming for the moment that the pontoon assembly may be made to rise and fall, as desired, in the position shown in Fig; 1 the chain net is suspended across the channel in such a way as to completely block the passage of a submarine boat, and the pontoons are kept below the water surface by the anchors M, an amount sufiicient to permit the passage of small boats l4. When water is admitted to the pontoons to reduce their buoyancy, the pontoon assembly, together with the chain net supported thereby, may sink to the bottom and rest thereon, thus freeing the channel for the passage of large ships. If desired, a trench may be dredged to receive this apparatus, as indicated by the dotted line |5 of Fig. 1.

When the arrangement shown in V to guard against the passage of submarine boats, itis desirable to have some form of indicator to disclose the presence of such a boat. For this Fig. 1 is used less diagrammatically in Figs. 4a and 4b. When a submarine boat contacts the net I9, it will put a strain on the pontoon anchor cables 6 and I, and this strain may be indicated by a pressure gauge through the following means: A hydraulic connector, or tension jack 20 may be located in one (or both) of the anchor cables 6 and l, and may comprise a cylinder 2|, having integral or attached tension members 22, with eyes 23, which may be connected to the cable 6, and a plunger 24, having a strap 25, with eyes 26, which may be connected to an end of cable 6.

A U packing leather 21 may hold the pressure developed by the strain on the cable 6, and this may be transferred through a flexible pipe 28, to a gauge 30, located at a convenient control point. The needle of the gauge 30 may be provided with a ratchet or some form of detent to record the pressure generated in cylinder 2|, until said detent is manually released.

This gives a visual indication of strain in the cable 6, and a measure or its'magnitude, but an audible indication is also desirable, and this may be obtained by continuing the pipe 28, by a pipe 29, to a small indicating cylinder 3|, having a plunger 32, acting against a spring 33.

When abnormal pressure reaches the plunger 32 it raises the same, and actuates a pivoted lever 34 to bring an attached electrical contact 35 against a ,fixed contact 36, and thus supply current from a battery 31 or other source, to an electric bell 40. The lever 34 may also be provided with a detent, so that the bell 40 will ring until the same is manually released.

Thus the presence of the submarineboat will be well indicated, and appropriate measures may be taken to dispose of, or capture it,

I will now describe the detailed construction of a preferred form of my improved pontoon assembly, and its method of operation when used as a skimming dam. In harbors and other water ways where ships are loaded with oil or gasoline, or in waters congested with shipping, and having contiguous docks or warehouses, and where oil is stored nearby in large tanks, or transported nearby in large pipe lines, leakage of oil from tanks or pipe lines to the harbor waters is a serious fire hazard, and when such leaks occur it is of advantage to be able to confine the floating oil to a limited area, or areas.

In many cases, depending on the typo raphy of the harbor, this may be done by floating skim ming dams, and if these dams are carried by a pontoon assembly such as herein disclosed, they may lie on the bottom, out of the way of shipping until needed, and then each of them, of all of them may be brought very promptly into working position at the water surface, with a portion of the structure projecting above said surface to restrict or prevent, the flow or movement of floating or wild oil, upon said water surface.

The pontoon supported skimming dam of Fig. 2 may be constructed as shown in Figs. 9-13, and be normally submerged-in a ditch I21, formed below the .channel bottom, so as to clear the hulls of passing ships of the deepest draught.

This dam maybe connected at each end to a vertical guide bar;|25, which may be a heavy steel pipe, having itslower end driven into, or anchored by a foundation to the channel bottom, and having its upper end supported from a dock or similar structure, as indicated in Fig. 2.

The pontoons are floated, or submerged, by the action of compressed air supplied from the shore through a flexible connection I26. The vertical movement of the pontoons from their lower position to their upper or floating position, will of course depend on the depth of the channel and may be from 30 to 50 ft. or more, and the length of the dams may vary from 100 feet to 1000 feet, or more.

Each pontoon I30 1 may consist of a hollow metal cylinder I3I, made of ordinary steel plate, rustless steel, or bronze, and having dished ends I32, preferably connected by welding, and forming an air tight structure except for a pair of discharge openings I28, both at the bottom of the pontoon, and one near each end thereof.

The pontoon I30 should preferably be of sufficient diameter to admit a man through a manhole I29, having a tight cover I33, and the length of the pontoons may vary from to 50 feet, as desired. These pontoons should be designed to have lateral stability of a reasonable amount when afloat.

Each pontoon I may have on its upper side, a dam I34, formed of a bent plate similar in section to an inverted U, and welded to the outer shell I3I. These dam I34 may be flexibly connected one to another, to form a continuous barrier for a quantity of floating oil or other material.

As shown in Figs. 10 and 11, the dam connecting member may bea bent plate or sheet I II, whose upper portion is given a U bend to fit loosely over the tops of two adjacent dams I34, and Whose lower portion I12 may conform to the shape of the pontoon I30, and rest thereon. Slotted holes I14 may be formed in the dams I34, and bolts I13 may loosely secure the connecting members I'II in place, with allowance for the relative movement of the pontoons.

As a substitute for the rigid member ill, the same may be replaced by a heavy woven mat of similar form, and made of asbestos or glass fiber, or other fire resisting material.

Below the shell I3I of each pontoon I30, there may be located a piece of steel pipe I35, (or other material) having closed ends, and secured to the shell I3I by a pair of plates I35, and preferably welded to said members.

The member I is a. reservoir for storing compressed air in readiness for immediate action, and its capacity must be such that it will store suflicient air under pressure to completely discharge the water in the shell I3I, when the pontoon is to be floated.

The reservoir I35, together with the plates I36, form a keel to give the pontoons, I30 lateral stability when afloat, and also form a smooth underbody which is not likely to stick in the mud of the harbor bottom, and interfere with floatation. Strainer I31 may be provided to cover the discharge openings I28.

Within the shell I3I, and connected to the reservoir I35, there is a valve chest I38, which may contain a poppet air valve, as shown in Fig. '7. This valve may be tightly seated by a spring I58, and opened by a push rod I39, operated by a small air cylinder I40 above the valve chest I38, and when this valve is so opened, compressed air from reservoir I35 may flow out of the short pipes I4l, to discharge the water from the shell I3], through the openings I28. The rapidity of such discharge may be fixed by the size of the air passages in the pipes I4I.

To supply the several cylinders I40 (one for each pontoon I30) with compressed air to operate the push rods I39, there is a continuous pipe line extending from pontoon to pontoon, and to a control station on the shore. As part of this line, pipes I42 are connected to the cylinder 140, one at each side thereof, and above the piston therein, and each of these pipes extends through one of the heads I32, into which itmay be welded.

Similarly, the several reservoirs I35 are connected to each other in series relation through pipes I43, so that the reservoirs maybe charged with compressed air from one (or both) ends of the pontoon line. To exhaust the air from the interior of the pontoon shell I3 I ,so that the pontoons may become submerged, I provide a pair of small piston operated vent valves I45, secured to the upper inner surface of the shell I3I, and connected to each other and to similar valves in adjacent pontoons by a continuous air line, of which the pipes I44 and I46 form a part. Each pipe I44 may extend through ahead I32, and be Welded thereto.

It will now, be seen that there are three separate air lines for operating the pontoons I30, with separate controls to be described later, as follows:

1. A line to charge the reservoirs I35, including the pipes I43.

2. A line to discharge the reservoirs I35, through the action of the valves-I38, and including the pipes I42, for floating the pontoons.

3. A line to vent the air from the pontoons through the valves I45, and the small vents I59, so they may sink, and including the pipes I44 and I46.

It is obvious that such a line of connected pontoons as herein proposed must be flexible, and to this end I provide hollow metal connectors I85, which have a central opening I41, and square flanged ends I48 (or other shape) to prevent relative rotation of the pontoons. Through the opening I41 three flexible rubber or metallic :air conduits I49 may be passed, which connect the respective adjacent pipes I42, I43, and I44, by suitable unions, to form continuous lines.

To each of the heads I32 there may be secured, preferably by welding, a retaining member I50 for the square ends I48, of the connectors I85. The members I50 may be formed in various ways. but I prefer to construct them in two parts, as shown in Figs. 11 and 12, and comprising a lower section I52, which may be rigidly and permanently attached to one of the heads I32, as by welding, and an upper section I5I, which may be detachably secured to the same by bolts I53.

Itwill be noted that each square end, or flange I48, is loosely confined between inner flanges I54, and outer flanges I55, both of these forming part of the members I50. This construction enables the pontoon connectors I to take either tension, compression, or twisting stresses, and to allow the adjacent pontoons to operate freely at a slight angle to each other, while at the same time preserving the general alignment of the chain of pontoons with sufficient accuracy for the intended purpose.

Referring to Fig. .13, a special bracket I56 may be provided for each of the two end pontoons of the line, in which is mounted a pivoted sleeve I51, to engage one of the vertical guides I25. To thepipes I 42, I43, and I44, emerging from the end pontoon near the guide I25, there may be connected flexible air conduits, each controlled by a valve at a control point on shore, and these three conduits may be enclosed in a heavy flexible protective cover I26, leading to supply pipes on shore.

The manual control of my pontoon assembly is accomplished as follows: The pontoons may be normally lying on the bottom with the reservoirs I35 fully 'chargediwith compressed air; It will benoted that the air pressure required will depend on the depthto which the pontoons are sunk, and must be suflicientlto startiforcing the water out of the shells I3'I 'at' that depth.

When it is desired'to raise'the pontoons, compressed air. from a storagelreservoir at the control point :may be admitted to pipe line I42, which, upon entering .the various cylinders I49 will depress their respective I pistons operating the push rods I39, and:open the air valves to permit of airfromeachIof the reservoirs I35 to blowout the contained water from its respective pontoon, thus raising all of the pontoons at the same time,,and'atsubstantially the same speed.

At any time later, air may :be supplied through the pipes I43, to recharge the reservoirs I35. The pontoons will float, as shown in Fig. 2, or will stay at their highest position, as shown in Fig. 1, as long as the water is'kept out of the pontoons by the air pressure in them.

When it is desired to' sink the pontoon assembly, air pressure is admitted to the connected pipes I44, and I46, which acts equally on the various-vent valves I45, thus'allowing the compressed airintheinteriorof the pontoons to escape through the'respective vents I59 in the upper portion ofthe'shell I3| of each pontoon, and allowing water to enterthe respective pontoon shells I3I through the holes I28 in their bottom portions. g

It will benoted that both the valves operated by the push rods I39, for blowing out the water from the pontoons, and the valves I45 for venting the air from the pontoons, are operated by the admission of air-pressure to parts connected to said valves, and by the transmission of the said pressure from'a stationary control point on shore.

Such action can be rendered automatic upon the occurrence of an earthquake, or a ground tremor due to an explosion, or bomb, in the following way.-

Referring to Fig. 14, the same shows a hollow metallic air pressure container I15, which may be connected to a line normally containing compressed an;

For instance, either of the pipe lines I42, or I44 may be connected to the container I15 by a pipe such; as 49 of Fig. 14, and the air may either pass through the container I15 on its way to do its work, or the container I15 may be at an end 'of the pipe. The essential condition is that if the container or any of its connected pressure holding parts is ruptured, the pressure within it, and within the connect-pipe lines will promptly escape to the atmosphere.

Attached to the upper side of the container I15 there are a number of glass tubes I16, preferably arranged in a circular row, and having closed upper ends and with their lower ends communicating with the interior of the container I15. At the center of this outer row of tubes there may be a single glass'tube I11 of similar form, :but shorter than the others. a .All of these glass tubes are subject to the fluid pressure in the container I15. Suspended by an elastic cord or spring I19, and located about in the center of the outer row-of tubes I16, there is a nietallicball or similar heavy object having suificient weight to easily break any of the glass tubes, and release the contained air pressure.

In the event of an earthquake, or a sharp ground shockdue to an explosion, the container I15;be ing Supported. more'or less rigidly by the ground, moves with it, while the weight I18, being suspended like a pendulum may remain still or have a different movement. If the ground movement is-horizontal these relative movements will break one of the tubes I16, and if the relative movement is vertical the ball I19 may contact the tube I11, break it, and release the pressure.

'In Fig. 5 I show how the reduction of pressure in a container such as I15 may act to apply pressure to a pipe such as I42, and thus cause the pontoons to rise.

The reservoir 59, which may be located at or near a convenient control point on shore, may be supplied with compressed air by a pipe 5| leading to any convenient source of pressure, and connecting the same to a cylinder 52, from which a second pipe 53 leads to reservoir 59. There may be a check valve 54 in the pipe 53 arranged to prevent the escape of air pressure from the reservoir 59.

A container I15 may be connected by a branch pipe 55 to the pipe 53, between the cylinder 52, and the check valve 54, and a ball I18 may be suspended in striking position above it.

The cylinder 52 may contain a piston 56, and below the piston 56 there may be placed a cylindrical valve 51, operating in a valve chest 59 concentric with the bore of cylinder 52. Both the members 56 and 51 may be secured to a stem 58, and the downward motion of these parts may be resisted by a spring 69.

A pipe 6| may lead from the reservoir 59 to the valve chest 59, and the pipe I42 for admitting air to the pontoon blow out valves, may also be connected to the valve chest 59 as shown in Fig. 5, so that in the position shown no air can pass the valve 51.

In the pipe 6| there may be a 3-way cock 62, for passing air pressure from the reservoir 59 to the valve chest 59, or for venting the pipes 6| and I42 to atmosphere when the valve 51 is in its raised or open position. A pressure gauge 53 may be provided for the reservoir 59, and vents 64' may be formed in member 59. Members 52 and 59 may be bolted together.

The operation of this apparatus is as follows: The reservoir 59 is charged through the pipes SI and 53, and normally contains compressed air under some predetermined pressure. This pressure forces the piston 56, and the valve 51 downward to the position shown, thus closing the valve against the spring 69.

When the valve 51 is closed; the 3-way valve 62 may be opened as shown to supply pressure to the valve 51 in readiness for use. The valve 62 is operated manually. If now the ball I18 contacts one of the breaker tubes I16 and breaks it, the pressure on piston 56 is quickly released, and the valve 51 rises and opens under the upward push of the spring 99.

Compressed air from the reservoir 59 may now fiowpast the valve 51 to the pipe I42 to perform its intended function, and the reservoir 59 must supply a volume of air sufficient to dothis. This action is an emergency action and may also exhaust reservoir 59. In order to again charge the reservoir 59, the 3-way cock is turned to close the outlet from the reservoir 59 via pipe 6|, and to vent the air from pipe I42 to the atmosphere. When this is accomplished, the pressure in reservoir 59 may be built up again, and when full pressure is reached the 3-way valve may be returned to the position shown, and as the valve 51 has already been closedby the re-established pressure in cylinder 52, the apparatus is again ready to supply compressed air automatically to pipe M22, as before.

The arrangement shown in Fig. is necessary when using the type of breaker tube I16 and container I15, but the control device illustrated in Fig. 6 may be used directly to admit air pressure to a conduit.

This is indicated in Fig, 6 where a valve or cook 65, having a lever handle 66, may be opened (or closed) by a falling weight I83. The weight I83 may be balanced on the cupped end of a bracket I82, over a hopper |8| having a lower aperture I84 large enough so that the ball I83 may fall through it when it is shaken off the bracket I82, and shatter a glass tube I80, set in the pipe 49, thus releasing the pressure in the pipe.

However, if the glass tube I80 be removed, and a valve or cock 65, be connected to the pipe 49 in any usual way so as to control the flow of fluid in said pipe, and with its lever handle 66 directly below the hopper opening I84, and in such a position that the ball I83 will strike the handle 66, and throw it over, the valve 65 may be either opened or closed by the descent of the ball, depending on which way the handle 65 projects from the valve 65, as will be readily seen.

It will thus be seen that I have provided two separate types of control devices, as shown respectively in Figs. 6, and 14, the device of Fig. 6

being adapted to either turn on, or turn off, the

pressure in an air line directly, and the device of Fig. 14 being adapted to release the pressure in an air line directly and to apply pressure to such a line indirectly and with the help of other connected elements.

The above description covers present preferred apparatus, and methods at present preferred for its operation, and is believed to be clear enough so that those skilled in the related arts may construct and use the same.

I claim:

1. Th method of preventing the dispersion of floating oil or combustible debris upon the surface of a ship channel or water way, comprising the vertical movement of a skimming dam extending across said water way, from a submerged position to a floating position in which its upper portion will extend above the water surface, and confine such oil or debris to a limited area.

2. The method of operating a flexibly connected line of submarine pontoons comprising the following steps: (a) Simultaneously charging individual reservoirs in each of the pontoons with compressed air; (1)) Simultaneously releasing air from each of said reservoirs into the interior of its respective pontoon to drive out the contained water, or a portion of it, to increase the buoyancy of adjacent pontoons by a substantially equal amount; (0) Simultaneously releasing the air within the pontoons in such a manner as to produce a substantially equal decrease in the buoyancy of adjacent pontoons.

3. The method of operating a skimming dam extending across a ship channel or water way, and permanently anchored in a desired location, comprising the following steps: (a) Submerging the dam to a depth sufiicient to clear the keels of passing ships, and maintaining the dam in said position indefinitely; (b) Raising the dam to a floating position at the surface of the water way at such times as it may be desired to confine the movement of floating oil or other combustible floating matter to one side o; the dam;

(c) Returning the dam to its normal submerged position in readiness for further action.

4. Th method of operating a skimming dam extending across a ship channel or water way and permanently located in a desired position, comprising the three consecutive steps set forth in claim 3, plus the further step of raising the dam immediately upon the occurrence of a distinct seismic shock.

5. The method of operating a flexibly connected line of metallic submarine pontoons placed across a waterway, from a lower to a higher level for the purpose described, comprising the raising or lowering of all the pontoons simultaneously in a substantially vertical path, and with all the pontoons normally at equal levels.

6. The method of preventing the dispersion of floating oil or combustible debris upon the surface of a ship channel or water way, by opposing a barrier to the surface movement of such material in such a manner that said barrier may be extended across said water way to form a skimming dam upon completing a bodily movement of less than the depth of water in said water way.

7. The method of operating a skimming dam at a desired point across a navigable ship channel or water way, comprising th bodily movement of said dam from an inoperative under water position below the draught of ships, in the shortest possible path to an operative position at the surface of the water, whereby emergency operation of said dam may be accomplished in the shortest practicable time.

8. The method of operating a skimming dam at a desired point across a navigable ship channel or water way, comprising the bodily movement of said dam in a direction substantially at a right angle to its length, from an inoperative to an operative position, and vice versa.

9. The method of moving a skimming dam from an inoperative under water position to a higher position, by the sudden application of large lifting forces equally distributed from end to end or said dam, whereby the said dam is brought to the surface of the water in readiness for immediate use, and in the least practicable time.

10. A normally submerged chain of flexibly connected pontoons, which when floating may form a skimming dam to prevent the spread of floating material upon the waters of a harbor or ship channel, and comprising a series of pontoons, each of which is provided with an individual reservoir for compressed air, means for positioning the said series of pontoons and guiding their vertical movement between floatation and submergence, means for charging the said air reservoirs, means for simultaneously passing air from each of said reservoirs to its connected pontoon, to blow out the contained water and float the pontoon, and means for venting the said air from all the pontoons at the same time, to allow them to submerge.

11. A line of flexibly connected submarine pontoons stretched across a water way and having its ends so secured at opposite sides of said water way that said chain of pontoons may be made to float or submerge at will by the simultaneous expulsion of water from the interiors of all of said pontoons, or the simultaneous admission of water thereto, means for expelling water from said pontoons by compressed air, means for admitting water to said pontoons, and separate means for controlling said admission and ex pulsion of water from 2 common control point on shore. a f

12. A submarine pontoon having an integral reservoir for compressed air located outside the pontoon shell, and having its center of gravity below the center of buoyancy of the pontoon shell, for lateral stability, means for charging said reservoir leisurely while the pontoon is submerged, and means including a pressure operated valve for admitting compressed air from said reservoir to the interior of the pontoon to quickly blow out some of the water therein and increase the buoyancy of the pontoon, and means for operating said valve.

13. The elements of claim 10, in combination with a separate pressure operated valve for each blow out means and each vent means on the pontoons, in combination with an operating valve for controlling all said blow out valves, and a second operating valve for controlling all said vent means, said operating valves being located at a control station on share.

14. A plurality of flexibly connected submarine pontoons, individual means in each pontoon for blowing out the contained water to float said pontoons, individual means for admitting water to the interior of each of said pontoons to sink them, sockets on the adjacent ends of adjacent pontoons to engage and retain the end of a connector, and a connector between adjacent pontoons having each of its ends shaped to permit only limited torsional movement in its socket and engaging one of said sockets in such a manner that a line of connected pontoons may have limited flexibility longitudinally, vertically, horizontally, and torsionally, with respect to each other.

l5. Aline of flexibly connected submarine pontoons adapted to be stretched across a ship channeland anchored at its ends to opposite sides thereof, a metallic net supported by said pontoons and adapted to close said channel to the-passage of submarine boats, and an indicating device adapted to give both visible and audible indications of the presence of a submarine boat in contact with said net, said device comprising means responsive to changes of tension in said line of pontoons for producing fluid pressure, a pressure responsive device for visually indicating said tension changes, and a second pressure responsive device for audibly indicating a considerable increase in said tension.

16. A line of flexibly connected rigid metallic pontoons adapted to be stretched across a ship channel and anchored there, a metallic fire resisting barrier wholly supported by said pontoons to prevent the movement of floating oil upon the water surface, means for sinking said pontoons to clear the channel for the passage of ships, and means for floating said pontoons at a higher level to make said barrier effective for the intended purpose.

17. A line of flexibly connected submarine pontoons, appropriate valves in each pontoon to control its buoyancy, means for simultaneously operating all the valves which cause the pontoons to rise, and similar means for simultaneously operating all the valves which cause the pontoons to submerge, and means for limiting the underwater rise of said pontoons to form a substantially level line at a predetermined distance below the surface of the water.

18. The combination or a line of flexibly connected pontoons arranged across a waterway, and adapted to lie normally on the bottom or to float at a lower level, and to rise by their buoyancy when the contained water is displaced and support useful marine apparatus, such as a skimming dam or a submarine net, suitable means for displacing said water, suitable control means for the normal operation of said displacing means, and automatic emergency means for actuating said control means to displace said water and allow said pontoons and their connected apparatus to rise to an efiective operating position upon the occurrence of a distinct seismic shock.

19. A line of flexibly connected submarine pontoons stretched across a water way, and having its ends so secured at opposite sides thereof that said line of pontoons may be caused to float or submerge by the simultaneous expulsion of water from the interior of all of said pontoons, or the simultaneous admission of water thereto, each of said pontoons comprising a hollow rigid metallic structure, and each pontoon having an integral reservoir for compressed air, a valve for admitting said air into the body of the pontoon to efiect the discharge of water therefrom, a valve controlling the exhaust of said air to permit the entrance of water, an opening through which water may enter, means for supplying compressed air to said reservoirs, means for operating said valves to permit the entrance or egress of water to or from the pontoons, and a continuous upwardly extending skimming dam secured to and supported by said line of pontoons, and located above them so as to project above water when said pontoons are afloat.

20. A line of flexibly connected submarine pontoons adapted to be stretched across a ship channel or water way, and to support a barrier for preventing the passage of water borne objects, each of said pontoons comprising a hollow cylinder with closed ends, a socket on each end of each of said pontoons except the two end pontoons, hollow connectors each having each of its ends engaging one of said sockets so as to connect two adjacent pontoons in a manner permitting a limited'amount of relative movement between them, an individual compressed air reservoir for each pontoon, a pipe passing through each end of each pontoon except the last one, and connecting to one of said reservoirs, a flexible conduit passing endwise through each of said connectors to connect said pipes, whereby compressed air may be forced into all of said pontoon reservoirs from one end of the line of pontoons, and stored therein ready for use, a pressure operated blow out valve in each of said pontoons, a continuous air line for operating said valves extending from one end of said pontoon line to the other end, and having flexible connecting conduits within said hollow connectors, a pressure operated vent valve in each pontoon, and a similar continuous air line extending through the aligned pontoons for operating said vent valves.

WALTER. W. MACFARREN. 

